doc: complete the table of symbols

[Akim Demaille]

commit 3e10504087ee8a0d533cc04cf75aa3f653b96dda
Author: Akim Demaille <address@hidden>
Date:   Fri May 8 07:31:19 2020 +0200

    doc: complete the table of symbols
    
    * doc/bison.texi: Add YYEMPTY, YYEOF and YYUNDEF.

diff --git a/doc/bison.texi b/doc/bison.texi
index 36f95258..7e51633b 100644
--- a/doc/bison.texi
+++ b/doc/bison.texi
@@ -7666,11 +7666,11 @@ recovery.
 In either case, the rest of the action is not executed.
 @end deffn
 
-@deffn {Macro} YYEMPTY
+@deffn {Value} YYEMPTY
 Value stored in @code{yychar} when there is no lookahead token.
 @end deffn
 
-@deffn {Macro} YYEOF
+@deffn {Value} YYEOF
 Value stored in @code{yychar} when the lookahead is the end of the input
 stream.
 @end deffn
@@ -14700,6 +14700,14 @@ is given a nonzero value, the parser will output 
information on input
 symbols and parser action.  @xref{Tracing}.
 @end deffn
 
+@deffn {Value} YYEMPTY
+The pseudo token kind when there is no lookahead token.
+@end deffn
+
+@deffn {Value} YYEOF
+The token kind denoting is the end of the input stream.
+@end deffn
+
 @deffn {Macro} yyerrok
 Macro to cause parser to recover immediately to its normal mode
 after a syntax error.  @xref{Error Recovery}.
@@ -14856,6 +14864,10 @@ should not be confused with the @emph{symbol kinds}, 
used internally by the
 parser.
 @end deffn
 
+@deffn {Value} YYUNDEF
+The token kind denoting an unknown token.
+@end deffn
+
 
 @node Glossary
 @appendix Glossary